I am looking to have a creature which is basically a small human sized bat, something like man-bat from the batman series. It would ideally fly or at least glide and would regularly hang upside down.
Assuming a human like form, I am worried about muscle strength holding up that much weight while having a light enough frame to glide, as well as blood rushing to the head. I want it to be as scientifically acceptable as possible to the point where it starts interfering significantly with basic humanoid tasks, where it will have to be hand-waved.
What biological features could I use to justify a bat-like creature of this size? Particularly issues of weight, bone strength, and blood rush when upside down.